Alpha alumina particles having average particle sizes of less than about 1.5 microns are known in the prior art. It is also known that alpha alumina particles can be made with a plate-like or tabular shape, in particle sizes greater than about 2 microns. However, alpha alumina particles having both plate-like shape and particle sizes below about 1.5 microns are heretofore unknown. As used herein with reference to platelets, the term "particle size" refers to the size of a largest dimension.
It is a principal objective of the present invention to provide alpha alumina particles having a plate-like shape with an average particle size below about 1.5 microns.
A related objective of the present invention is to provide an economical process for production of alpha alumina particles of the type described, which process avoids formation of boehmite gel at an intermediate stage.
Additional objectives and advantages of the present invention will become apparent to persons skilled in the art from the following specification and claims.